Two epithelioid malignant schwannomas in a patient with neurofibromatosis. Cytology, histology and DNA-flow-cytometry.

Cytological, histological and DNA-ploidy findings of 2 epithelioid malignant schwannomas arising in a patient with von Recklinghausen's neurofibromatosis are described. In both primary tumors, i.e. in the thigh and in the thoracic wall, origin from a neurofibromatous nerve could be established. Within 2 years after the manifestation of the first malignant tumor the patient died of widely metastasized disease. DNA-flow cytometry of several neurofibromas revealed diploid stemlines, but both malignant primary tumors and a lung metastasis appeared to be aneuploid. Presumably, the primary tumors also contained cell populations with a diploid stem line.